THOR / Synthorx Inc - Pengajuan SECLaporan Tahunan, Pernyataan Proksi

Synthorx Inc
US ˙ NASDAQ ˙ US87167A1034
HINDI NA ACTIVE ANG SIMBONG ITO

Mga Batayang Estadistika
CIK 1609727
SEC Filings
All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to Synthorx Inc
SEC Filings (Chronological Order)
Halaman ini menyediakan daftar lengkap dan kronologis dari Pengajuan SEC, tidak termasuk pengajuan kepemilikan yang kami sediakan di tempat lain.
February 14, 2020 EX-1

JOINT FILING AGREEMENT

EX-1 2 thor13g2019ex1filed.htm JOINT FILING AGREEMENT EXHIBIT 1 JOINT FILING AGREEMENT This Joint Filing Agreement dated February 14, 2020 is by and between Camber Capital Management LP, a Delaware limited partnership, and Stephen DuBois, an individual (the foregoing are collectively referred to herein as the "Filers"). Each of the Filers may be required to file with the United States Securities a

February 14, 2020 SC 13G/A

87167A103 / Synthorx Inc / Camber Capital Management LLC - PRIMARY DOCUMENT Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2) Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 87167A103 (CUSIP Number) December 31, 2019 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule purs

February 3, 2020 15-12B

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13

15-12B UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number 001-38756 Synthorx, Inc. (Exact name of registrant as specified in its

January 23, 2020 EX-3.2

Second Amended and Restated Bylaws of the Company.

EX-3.2 3 d858447dex32.htm EX-3.2 Exhibit 3.2 SECOND AMENDED AND RESTATED BYLAWS OF SYNTHORX, INC. (a Delaware corporation) ARTICLE I Stockholders SECTION 1. Annual Meetings. The annual meeting of the stockholders of Thunder Acquisition Corp. (the “Corporation”) for the election of directors and for the transaction of such other business as may properly come before the meeting shall be held each ye

January 23, 2020 SC 14D9/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 (Amendment No. 4) Synthorx, Inc. (Name of Subjec

SC 14D9/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 (Amendment No. 4) Synthorx, Inc. (Name of Subject Company) Synthorx, Inc. (Name of Person Filing Statement) Common Stock, $0.001 par value per share (Title of Class of Securities) 87167A10

January 23, 2020 S-8 POS

As filed with the Securities and Exchange Commission on January 23, 2020

As filed with the Securities and Exchange Commission on January 23, 2020 Registration No.

January 23, 2020 EX-3.1

Amended and Restated Certificate of Incorporation of the Company.

EX-3.1 2 d858447dex31.htm EX-3.1 Exhibit 3.1 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF SYNTHORX, INC. FIRST: The name of the corporation is Synthorx, Inc. (the “Corporation”). SECOND: The address of the registered office of the Corporation in the State of Delaware is: Corporation Service Company, 251 Little Falls Drive, Wilmington, DE 19808, County of New Castle. The name of its registe

January 23, 2020 S-8 POS

As filed with the Securities and Exchange Commission on January 23, 2020

As filed with the Securities and Exchange Commission on January 23, 2020 Registration No.

January 23, 2020 SC TO-T/A

SNY / Sanofi SC TO-T/A - - AMENDMENT NO. 4 TO SCHEDULE TO

SC TO-T/A 1 d867235dsctota.htm AMENDMENT NO. 4 TO SCHEDULE TO UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 (Amendment No. 4) Synthorx, Inc. (Name of Subject Company (Issuer)) THUNDER ACQUISITION CORP. AVENTIS INC. SANOFI (Names of Filing Persons — Offerors) Common

January 23, 2020 8-K

Changes in Control of Registrant, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Material Modification to Rights of Security Holders, Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Financial Statements and Exhibits, Completion of Acquisition or Disposition of Assets

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 23, 2020 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File Nu

January 21, 2020 SC 14D9/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 (Amendment No. 3) Synthorx, Inc. (Name of Subjec

SC 14D9/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 (Amendment No. 3) Synthorx, Inc. (Name of Subject Company) Synthorx, Inc. (Name of Person Filing Statement) Common Stock, $0.001 par value per share (Title of Class of Securities) 87167A10

January 21, 2020 EX-99.(A)(5)(J)

Source: Sanofi (EURONEXT: SAN) (NASDAQ: SNY)

EX-99.(A)(5)(J) 2 d856841dex99a5j.htm EXHIBIT (A)(5)(J) Exhibit (a)(5)(J) Press Release Source: Sanofi (EURONEXT: SAN) (NASDAQ: SNY) Hart-Scott-Rodino waiting period expires for Sanofi’s acquisition of Synthorx Paris – January 20, 2020 – Sanofi announced today that the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”), applicable to Sanofi’s

January 21, 2020 SC TO-T/A

SNY / Sanofi SC TO-T/A - - AMENDMENT NO. 3 TO SCHEDULE TO

Amendment No. 3 to Schedule TO UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 (Amendment No. 3) Synthorx, Inc. (Name of Subject Company (Issuer)) THUNDER ACQUISITION CORP. AVENTIS INC. SANOFI (Names of Filing Persons — Offerors) Common Stock, Par Value $0.001 Per Sh

January 15, 2020 SC 14D9/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 (Amendment No. 2) Synthorx, Inc. (Name of Subjec

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 (Amendment No. 2) Synthorx, Inc. (Name of Subject Company) Synthorx, Inc. (Name of Person Filing Statement) Common Stock, $0.001 par value per share (Title of Class of Securities) 87167A103 (CUSIP N

January 14, 2020 CORRESP

Cooley LLP 4401 Eastgate Mall San Diego, CA 92121-1909 t: (858) 550-6000 f: (858) 550-6420 cooley.com

CORRESP Rama Padmanabhan +1 858 550 6024 [email protected] January 14, 2020 Nicholas P. Panos Senior Special Counsel U.S. Securities and Exchange Commission Division of Corporation Finance Office of Mergers and Acquisitions 100 F Street, N.E. Washington, D.C. 20549 Re: Synthorx, Inc. Schedule 14D-9 filed by Synthorx, Inc. on December 23, 2019 File No. 005-90741 Dear Mr. Panos: On behalf of Synthorx,

January 9, 2020 SC TO-T/A

SNY / Sanofi SC TO-T/A - - AMENDMENT NO. 2 TO SC TO-T

Amendment No. 2 to SC TO-T UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 (Amendment No. 2) Synthorx, Inc. (Name of Subject Company (Issuer)) THUNDER ACQUISITION CORP. AVENTIS INC. SANOFI (Names of Filing Persons — Offerors) Common Stock, Par Value $0.001 Per Share

January 7, 2020 EX-99.(E)(15)

Synthorx, Inc. 11099 N. Torrey Pines Road, Suite 190 La Jolla, CA 92037

Exhibit (e)(15) Synthorx, Inc. 11099 N. Torrey Pines Road, Suite 190 La Jolla, CA 92037 December 30, 2019 [Recipient] Re: Certain Compensation Matters Dear [Recipient], As you know, Synthorx, Inc. (the ?Company?) has entered into an Agreement and Plan of Merger, dated December 7, 2019 (the ?Merger Agreement?) with Sanofi, a French soci?t? anonyme (?Parent?) and Thunder Acquisition Corp., a wholly-

January 7, 2020 SC TO-T/A

SNY / Sanofi SC TO-T/A - - AMENDMENT NO. 1 TO SC TO-T

Amendment No. 1 to SC TO-T UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 (Amendment No. 1) Synthorx, Inc. (Name of Subject Company (Issuer)) THUNDER ACQUISITION CORP. AVENTIS INC. SANOFI (Names of Filing Persons — Offerors) Common Stock, Par Value $0.001 Per Share

January 7, 2020 SC 14D9/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 (Amendment No. 1) Synthorx, Inc. (Name of Subjec

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 (Amendment No. 1) Synthorx, Inc. (Name of Subject Company) Synthorx, Inc. (Name of Person Filing Statement) Common Stock, $0.001 par value per share (Title of Class of Securities) 87167A103 (CUSIP N

January 7, 2020 CORRESP

Cooley LLP 4401 Eastgate Mall San Diego, CA 92121-1909 t: (858) 550-6000 f: (858) 550-6420 cooley.com

CORRESP Rama Padmanabhan +1 858 550 6024 [email protected] January 7, 2020 Nicholas P. Panos Senior Special Counsel U.S. Securities and Exchange Commission Division of Corporation Finance Office of Mergers and Acquisitions 100 F Street, N.E. Washington, D.C. 20549 Re: Synthorx, Inc. Schedule 14D-9 filed by Synthorx, Inc. on December 23, 2019 File No. 005-90741 Dear Mr. Panos: On behalf of Synthorx,

December 27, 2019 SC TO-T

SNY / Sanofi SC TO-T - - SC TO-T

SC TO-T UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Synthorx, Inc. (Name of Subject Company (Issuer)) THUNDER ACQUISITION CORP. AVENTIS INC. SANOFI (Names of Filing Persons — Offerors) Common Stock, Par Value $0.001 Per Share (Title of Class of Securities) 87167A

December 27, 2019 EX-99.(A)(1)(B)

LETTER OF TRANSMITTAL To Tender Shares of Common Stock SYNTHORX, INC. $68.00 Per Share, Net in Cash Pursuant to the Offer to Purchase dated December 23, 2019 THUNDER ACQUISITION CORP. a wholly owned indirect subsidiary

EX-99.(A)(1)(B) 3 d851633dex99a1b.htm EX-99.(A)(1)(B) Exhibit (a)(1)(B) LETTER OF TRANSMITTAL To Tender Shares of Common Stock of SYNTHORX, INC. at $68.00 Per Share, Net in Cash Pursuant to the Offer to Purchase dated December 23, 2019 by THUNDER ACQUISITION CORP. a wholly owned indirect subsidiary of SANOFI THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT ONE MINUTE PAST 11:59 P.M., EASTERN TIME, O

December 27, 2019 SC14D9C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 (Amendment No. 1) SYNTHORX, INC. (Name of Subjec

SC14D9C 1 d855139dsc14d9c.htm SC14D9C UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 (Amendment No. 1) SYNTHORX, INC. (Name of Subject Company) SYNTHORX, INC. (Name of Person Filing Statement) Common Stock, $0.001 par value per share (Title of C

December 27, 2019 EX-99.(D)(2)

CONFIDENTIALITY AGREEMENT

EX-99.(d)(2) Exhibit (d)(2) CONFIDENTIALITY AGREEMENT THIS CONFIDENTIALITY AGREEMENT (“Agreement”) is being entered into as of December 3, 2019, between SYNTHORX, INC., a Delaware corporation (the “Company”), and SANOFI, a French corporation (“Counterparty”). The Company and Counterparty (referred to collectively as the “Parties” and individually as a “Party”) are also parties to that certain Conf

December 27, 2019 EX-99.(A)(1)(F)

Notice of Offer to Purchase All Outstanding Shares of Common Stock SYNTHORX, INC. $68.00 PER SHARE, NET IN CASH Pursuant to the Offer to Purchase dated December 23, 2019 THUNDER ACQUISITION CORP. a wholly owned indirect subsidiary

EX-99.(a)(1)(F) Exhibit (a)(1)(F) This announcement is neither an offer to purchase nor a solicitation of an offer to sell Shares (as defined below). The Offer (as defined below) is made only by the Offer to Purchase, dated December 23, 2019, and the related Letter of Transmittal and any amendments or supplements thereto, and is being made to all holders of Shares. The Offer is not being made to (

December 27, 2019 EX-99.(A)(1)(C)

NOTICE OF GUARANTEED DELIVERY To Tender Shares of Common Stock SYNTHORX, INC. $68.00 PER SHARE, NET IN CASH Pursuant to the Offer to Purchase dated December 23, 2019 THUNDER ACQUISITION CORP. a wholly owned indirect subsidiary

EX-99.(a)(1)(C) Exhibit (a)(1)(C) NOTICE OF GUARANTEED DELIVERY To Tender Shares of Common Stock of SYNTHORX, INC. at $68.00 PER SHARE, NET IN CASH Pursuant to the Offer to Purchase dated December 23, 2019 by THUNDER ACQUISITION CORP. a wholly owned indirect subsidiary of SANOFI THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT ONE MINUTE PAST 11:59 P.M., EASTERN TIME, ON JANUARY 22, 2020, UNLESS THE

December 27, 2019 EX-2.1

AGREEMENT AND PLAN OF MERGER Synthorx, Inc., a Delaware corporation; a French société anonyme; and Thunder Acquisition Corp., a Delaware corporation Dated as of December 7, 2019

Exhibit 2.1 AGREEMENT AND PLAN OF MERGER among: Synthorx, Inc., a Delaware corporation; SANOFI, a French soci?t? anonyme; and Thunder Acquisition Corp., a Delaware corporation Dated as of December 7, 2019 TABLE OF CONTENTS Page SECTION 1. THE OFFER 2 1.1 The Offer 2 1.2 Company Actions 4 SECTION 2. MERGER TRANSACTION 5 2.1 Merger of Purchaser into the Company 5 2.2 Effect of the Merger 5 2.3 Closi

December 27, 2019 EX-99.(A)(1)(A)

Offer To Purchase All Outstanding Shares of Common Stock SYNTHORX, INC. $68.00 Per Share, Net in Cash THUNDER ACQUISITION CORP., a wholly owned indirect subsidiary of

EX-99.(a)(1)(A) Table of Contents Exhibit (a)(1)(A) Offer To Purchase All Outstanding Shares of Common Stock of SYNTHORX, INC. at $68.00 Per Share, Net in Cash by THUNDER ACQUISITION CORP., a wholly owned indirect subsidiary of SANOFI THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT ONE MINUTE PAST 11:59 P.M., EASTERN TIME, ON JANUARY 22, 2020, UNLESS THE OFFER IS EXTENDED OR EARLIER TERMINATED. Thu

December 27, 2019 EX-99.2

December 8, 2019

EX-99.2 4 d855139dex992.htm EX-99.2 Exhibit 99.2 December 8, 2019 Dear Synthorx Employees, I have exciting news to share with you about a significant announcement we have made describing Sanofi’s intent to acquire Synthorx. Attached is a copy of the press release announcing the proposed transaction. As a company, we have one-of-a-kind DNA and as individuals we are all unique, but together we have

December 27, 2019 CORRESP

Cooley LLP 4401 Eastgate Mall San Diego, CA 92121-1909 t: (858) 550-6000 f: (858) 550-6420 cooley.com

CORRESP Rama Padmanabhan +1 858 550 6024 [email protected] December 27, 2019 U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attn: Nicholas P. Panos Re: Synthorx, Inc. Schedule 14d-9 filed by Synthorx, Inc. on December 9, 2019 File No. 005-90741 Dear Mr. Panos: On behalf of Synthorx, Inc. (the “Company”), we are responding to t

December 27, 2019 EX-99.(D)(3)

EXCLUSIVITY AGREEMENT

EX-99.(d)(3) Exhibit (d)(3) EXCLUSIVITY AGREEMENT This Exclusivity Agreement (this “Agreement”) is entered into as of December 3, 2019, by and between Synthorx Inc, a Delaware corporation (the “Company”) and Sanofi (with its affiliates, “Counterparty”). The parties have engaged in preliminary discussions regarding the terms of a negotiated acquisition of the Company (the “Transaction”) by Counterp

December 27, 2019 EX-99.(A)(1)(E)

Offer to Purchase All Outstanding Shares of Common Stock SYNTHORX, INC. $68.00 PER SHARE, NET IN CASH Pursuant to the Offer to Purchase dated December 23, 2019 THUNDER ACQUISITION CORP. a wholly owned indirect subsidiary

EX-99.(a)(1)(E) Exhibit (a)(1)(E) Offer to Purchase All Outstanding Shares of Common Stock of SYNTHORX, INC. at $68.00 PER SHARE, NET IN CASH Pursuant to the Offer to Purchase dated December 23, 2019 by THUNDER ACQUISITION CORP. a wholly owned indirect subsidiary of SANOFI THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT ONE MINUTE PAST 11:59 P.M., EASTERN TIME, ON JANUARY 22, 2020, UNLESS THE OFFER

December 27, 2019 EX-99.(A)(5)(I)

Source: Sanofi (EURONEXT: SAN) (NYSE: SNY)

EX-99.(A)(5)(I) 8 d851633dex99a5i.htm EX-99.(A)(5)(I) Exhibit (a)(5)(I) Press Release Source: Sanofi (EURONEXT: SAN) (NYSE: SNY) Sanofi commences tender offer for acquisition of Synthorx, Inc. PARIS – December 23, 2019 – Sanofi announced today that it intends to commence a tender offer (the “Offer”) today to acquire all of the outstanding shares of common stock of Synthorx, Inc. (“Synthorx”) for $

December 27, 2019 EX-99.1

Source: Sanofi (EURONEXT: SAN) (NYSE: SNY)

EX-99.1 3 d855139dex991.htm EX-99.1 Exhibit 99.1 Press Release Source: Sanofi (EURONEXT: SAN) (NYSE: SNY) Sanofi to acquire Synthorx to bolster its immuno-oncology pipeline for $2.5 Billion • Proprietary immuno-oncology (IO) platform synergistic with Sanofi’s existing therapeutic platforms • Lead asset THOR-707 (“not-alpha” IL-2) being explored across multiple solid tumor types alone and in combin

December 27, 2019 EX-99.(A)(1)(D)

Offer to Purchase All Outstanding Shares of Common Stock SYNTHORX, INC. $68.00 PER SHARE, NET IN CASH Pursuant to the Offer to Purchase dated December 23, 2019 THUNDER ACQUISITION CORP. a wholly owned indirect subsidiary

EX-99.(A)(1)(D) 5 d851633dex99a1d.htm EX-99.(A)(1)(D) Exhibit (a)(1)(D) Offer to Purchase All Outstanding Shares of Common Stock of SYNTHORX, INC. at $68.00 PER SHARE, NET IN CASH Pursuant to the Offer to Purchase dated December 23, 2019 by THUNDER ACQUISITION CORP. a wholly owned indirect subsidiary of SANOFI THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT ONE MINUTE PAST 11:59 P.M., EASTERN TIME,

December 23, 2019 EX-99.(E)(14)

EXCLUSIVITY AGREEMENT

Exhibit (e)(14) EXCLUSIVITY AGREEMENT This Exclusivity Agreement (this ?Agreement?) is entered into as of December 3, 2019, by and between Synthorx Inc, a Delaware corporation (the ?Company?) and Sanofi (with its affiliates, ?Counterparty?).

December 23, 2019 EX-99.(E)(13)

CONFIDENTIALITY AGREEMENT

Exhibit (e)(13) CONFIDENTIALITY AGREEMENT THIS CONFIDENTIALITY AGREEMENT (?Agreement?) is being entered into as of December 3, 2019, between SYNTHORX, INC.

December 23, 2019 SC 14D9

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 Synthorx, Inc. (Name of Subject Company) Synthor

SC 14D9 Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

December 11, 2019 SC TO-C

SNY / Sanofi SC TO-C - - SC TO-C

SC TO-C UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Synthorx, Inc. (Name of Subject Company) THUNDER ACQUISITION CORP. AVENTIS INC. SANOFI (Names of Filing Persons — Offerors) Common Stock, Par Value $0.001 Per Share (Title of Class of Securities) 87167A103 (Cusi

December 11, 2019 EX-99.1

Capital Markets Day Play to Win December 10, 2019 SANOFI

EX-99.1 2 d844499dex991.htm EX-99.1 Exhibit 99.1 Capital Markets Day Play to Win December 10, 2019 SANOFI Forward looking statements This presentation contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. These statements include projections and estimates and their

December 10, 2019 SC TO-C

SNY / Sanofi SC TO-C - - SC TO-C

SC TO-C UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Synthorx, Inc. (Name of Subject Company) THUNDER ACQUISITION CORP. AVENTIS INC. SANOFI (Names of Filing Persons — Offerors) Common Stock, Par Value $0.001 Per Share (Title of Class of Securities) 87167A103 (Cusi

December 9, 2019 EX-99.5

1

EX-99.5 Exhibit 99.5 Message from John Reed—Sanofi to acquire Synthorx December 9th, 2019 Dear Colleagues, Today we announced Sanofi’s plans to acquire Synthorx, a clinical-stage biotechnology company focused on prolonging and improving the lives of people with cancer and autoimmune disorders. Both the company’s pipeline and their platform technology are attractive to us. See the press release her

December 9, 2019 EX-99.3

2

EX-99.3 Exhibit 99.3 Social Media Posts 9 December 2019 Twitter: LinkedIn: 2

December 9, 2019 EX-99.2

December 8, 2019

EX-99.2 Exhibit 99.2 December 8, 2019 Dear Synthorx Employees, I have exciting news to share with you about a significant announcement we have made describing Sanofi’s intent to acquire Synthorx. Attached is a copy of the press release announcing the proposed transaction. As a company, we have one-of-a-kind DNA and as individuals we are all unique, but together we have always been one for patients

December 9, 2019 SC14D9C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 SYNTHORX, INC. (Name of Subject Company) SYNTHOR

SC14D9C 1 d697751dsc14d9c.htm SC14D9C UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 SYNTHORX, INC. (Name of Subject Company) SYNTHORX, INC. (Name of Person Filing Statement) Common Stock, $0.001 par value per share (Title of Class of Securities

December 9, 2019 EX-2.1

Agreement and Plan of Merger, dated as of December 7, 2019, by and among Synthorx, Inc., Sanofi and Thunder Acquisition Corp.

Exhibit 2.1 AGREEMENT AND PLAN OF MERGER among: Synthorx, Inc., a Delaware corporation; SANOFI, a French soci?t? anonyme; and Thunder Acquisition Corp., a Delaware corporation Dated as of December 7, 2019 TABLE OF CONTENTS Page SECTION 1. THE OFFER 2 1.1 The Offer 2 1.2 Company Actions 4 SECTION 2. MERGER TRANSACTION 5 2.1 Merger of Purchaser into the Company 5 2.2 Effect of the Merger 5 2.3 Closi

December 9, 2019 EX-99.(II)

Dear Synthorx Colleagues,

Exhibit (ii) Dear Synthorx Colleagues, Today, Synthorx and Sanofi announced plans to bring Synthorx into the Sanofi family.

December 9, 2019 EX-99.(I)

Synthorx, Inc. - Employee Questions and Answers

Exhibit (i) Synthorx, Inc. - Employee Questions and Answers 1. What was announced regarding the Company and Sanofi? Synthorx, Inc. (the ?Company? or ?Synthorx?) and Sanofi (?Sanofi?) have entered into a definitive merger agreement for Sanofi to acquire the Company at a price of $68.00 per share in a cash transaction, a significant premium over the previous trading price of the Company?s common sto

December 9, 2019 SC TO-C

SNY / Sanofi SC TO-C - - SC TO-C

SC TO-C UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Synthorx, Inc. (Name of Subject Company) THUNDER ACQUISITION CORP. AVENTIS INC. SANOFI (Names of Filing Persons — Offerors) Common Stock, Par Value $0.001 Per Share (Title of Class of Securities) 87167A103 (Cusi

December 9, 2019 EX-99.4

Dear Synthorx Colleagues,

EX-99.4 Exhibit 99.4 Dear Synthorx Colleagues, Today, Synthorx and Sanofi announced plans to bring Synthorx into the Sanofi family. As the Head of Research and Development at Sanofi, I am tremendously excited at the prospect of uniting our teams to develop transformative medicines for patients with cancer and immunological disorders. In our meetings with senior leaders at Synthorx, we have discove

December 9, 2019 EX-99.1

Source: Sanofi (EURONEXT: SAN) (NYSE: SNY)

EX-99.1 3 d838663dex991.htm EX-99.1 Exhibit 99.1 Press Release Source: Sanofi (EURONEXT: SAN) (NYSE: SNY) Sanofi to acquire Synthorx to bolster its immuno-oncology pipeline for $2.5 Billion • Proprietary immuno-oncology (IO) platform synergistic with Sanofi’s existing therapeutic platforms • Lead asset THOR-707 (“not-alpha” IL-2) being explored across multiple solid tumor types alone and in combin

December 9, 2019 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 5, 2019 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File Nu

December 9, 2019 SC14D9C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 SYNTHORX, INC. (Name of Subject Company) SYNTHOR

SC14D9C 1 d805291dsc14d9c.htm SC14D9C UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14D-9 (Rule 14d-101) Solicitation/Recommendation Statement Under Section 14(d)(4) of the Securities Exchange Act of 1934 SYNTHORX, INC. (Name of Subject Company) SYNTHORX, INC. (Name of Person Filing Statement) Common Stock, $0.001 par value per share (Title of Class of Securities

December 9, 2019 EX-99.2

December 8, 2019

EX-99.2 4 d838663dex992.htm EX-99.2 Exhibit 99.2 December 8, 2019 Dear Synthorx Employees, I have exciting news to share with you about a significant announcement we have made describing Sanofi’s intent to acquire Synthorx. Attached is a copy of the press release announcing the proposed transaction. As a company, we have one-of-a-kind DNA and as individuals we are all unique, but together we have

December 9, 2019 EX-99.6

Synthorx, Inc. - Employee Questions and Answers

EX-99.6 Exhibit 99.6 Synthorx, Inc. - Employee Questions and Answers 1. What was announced regarding the Company and Sanofi? Synthorx, Inc. (the “Company” or “Synthorx”) and Sanofi (“Sanofi”) have entered into a definitive merger agreement for Sanofi to acquire the Company at a price of $68.00 per share in a cash transaction, a significant premium over the previous trading price of the Company’s c

December 9, 2019 EX-99.1

Source: Sanofi (EURONEXT: SAN) (NYSE: SNY)

Exhibit 99.1 Press Release Source: Sanofi (EURONEXT: SAN) (NYSE: SNY) Sanofi to acquire Synthorx to bolster its immuno-oncology pipeline for $2.5 Billion • Proprietary immuno-oncology (IO) platform synergistic with Sanofi’s existing therapeutic platforms • Lead asset THOR-707 (“not-alpha” IL-2) being explored across multiple solid tumor types alone and in combination with immune checkpoint inhibit

November 8, 2019 EX-99.1

Discovery of Pharmacologically Differentiated Interleukin 15 (IL-15) Agonists Employing a Synthetic Biology Platform

EX-99.1 2 d805399dex991.htm EX-99.1 Exhibit 99.1 Discovery of Pharmacologically Differentiated Interleukin 15 (IL-15) Agonists Employing a Synthetic Biology Platform Carolina E. Caffaro; Jerod L. Ptacin; Rob W. Herman; Lina Ma; David B. Chen; Nicole Acuff; Kristine M. San Jose; Kelsea Loescher; Jill Mooney; Ingrid B. Joseph; Marcos E. Milla Synthorx, Inc., La Jolla, CA Discovery of Pharmacological

November 8, 2019 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 8, 2019 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File Nu

November 8, 2019 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 8, 2019 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File Nu

November 8, 2019 EX-99.2

Using a Novel Synthetic Biology Platform to Generate a Homogeneous Dipegylated IL-10 With Native Potency

EX-99.2 3 d805445dex992.htm EX-99.2 Exhibit 99.2 Using a Novel Synthetic Biology Platform to Generate a Homogeneous Dipegylated IL-10 With Native Potency Carolina E. Caffaro; Jerod L. Ptacin; Nicole Acuff; Yelena Pavlova; Jasmine Nguyen; Kristine M. San Jose; Gavin Hong; Lina Ma; Taylor Ismaili; Kelsea Loescher; Ingrid B. Joseph; Jill Mooney; Joseph A. Leveque; Marcos E. Milla Synthorx, Inc., La J

November 8, 2019 EX-99.3

THOR-809: An IL-2 Engineered From an Expanded Genetic Alphabet for the Potential Treatment of Autoimmune Disorders

EX-99.3 4 d805445dex993.htm EX-99.3 Exhibit 99.3 THOR-809: An IL-2 Engineered From an Expanded Genetic Alphabet for the Potential Treatment of Autoimmune Disorders Marcos E. Milla; Carolina E. Caffaro; Lina Ma; Ingrid B. Joseph; David B. Chen; Taylor Ismaili; Kristine M. San Jose; Yelena Pavlova; Namit Singh; Lilia K. Koriazova; Hans R. Aerni; Michael J. Pena; Jerod L. Ptacin INTRODUCTION " CD4+ r

November 8, 2019 EX-99.1

An Open-Label, Multicenter Phase 1/2 Dose Escalation and Expansion Study of THOR-707 as a Single Agent and in Combination with Pembrolizumab in Adult Subjects with Advanced or Metastatic Solid Tumors

EX-99.1 2 d805445dex991.htm EX-99.1 Exhibit 99.1 An Open-Label, Multicenter Phase 1/2 Dose Escalation and Expansion Study of THOR-707 as a Single Agent and in Combination with Pembrolizumab in Adult Subjects with Advanced or Metastatic Solid Tumors David Luo;1 Raghad Abdul-Karim;2 Arun Azad;3 Joanna Bendell;4 Hui Gan;5 Filip Janku;6 Shiraj Sen;7 Tira Tan;8 Judy Wang;9 Lisa Schechet;1 Lauren Baker;

November 5, 2019 EX-99.1

Synthorx Reports Third Quarter Financial Results

EX-99.1 2 thor-ex9916.htm EX-99.1 Exhibit 99.1 Synthorx Reports Third Quarter Financial Results SAN DIEGO, CA – November 5, 2019 (GLOBE NEWSWIRE) - Synthorx, Inc. (Nasdaq: THOR), a clinical-stage biotechnology company developing optimized therapeutics for cancer and autoimmune disorders, today reported financial results and provided a business update for the third quarter ended September 30, 2019.

November 5, 2019 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8?K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 5, 2019 Synthorx, Inc.

November 5, 2019 EX-10.3

Sub-Sublease Agreement dated August 30, 2019, by and between the Registrant and Avelas Biosciences, Inc.

EXHIBIT 10.3 SUB-SUBLEASE (San Diego, California) This Sub-Sublease (this ?Sub-Sublease?) is entered into as of August 30, 2019 (the ?Effective Date?), by and between Avelas Biosciences, Inc., a Delaware corporation (?Sub-Sublandlord?), and Synthorx, Inc., a Delaware corporation (?Sub-Subtenant?). Sub-Sublandlord and Sub-Subtenant may each be referred to herein as a ?Party?, and collectively, the

November 5, 2019 EX-10.2

Fifth Amendment to Research Funding and Option Agreement dated July 31, 2019, by and between the Registrant and The Scripps Research Institute.

EX-10.2 3 thor-ex102260.htm EX-10.2 EXHIBIT 10.2 CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [***], HAS BEEN OMITTED BECAUSE SYNTHORX, INC. HAS DETERMINED THE INFORMATION (I) IS NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM TO SYNTHORX, INC. IF PUBLICLY DISCLOSED. CONFIDENTIAL FIFTH AMENDMENT to RESEARCH FUNDING AND OPTION AGREEMENT This Fifth Amendment (“Fif

November 5, 2019 EX-10.1

Second Amendment to License Agreement, dated August 5, 2019 by and between the Registrant and The Scripps Research Institute.

EXHIBIT 10.1 CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [***], HAS BEEN OMITTED BECAUSE SYNTHORX, INC. HAS DETERMINED THE INFORMATION (I) IS NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM TO SYNTHORX, INC. IF PUBLICLY DISCLOSED. SECOND AMENDMENT TO LICENSE AGREEMENT This is an Amendment, dated as of August 5, 2019 (this ?Second Amendment?), to the License Agr

November 5, 2019 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38756 SYNTH

September 30, 2019 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 30, 2019 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File

September 30, 2019 EX-99.1

THOR-707, a Novel Not-alpha IL-2, Promotes All Key Immune System Anti-tumoral Actions of IL-2 Without Eliciting Vascular Leak Syndrome (VLS)

Exhibit 99.1 THOR-707, a Novel Not-alpha IL-2, Promotes All Key Immune System Anti-tumoral Actions of IL-2 Without Eliciting Vascular Leak Syndrome (VLS) Marcos E. Milla; Jerod L. Ptacin; Lina Ma; Carolina E. Caffaro; Hans R. Aerni; Kristine M. San Jose; Michael J. Pena; Robert W. Herman; Yelena Pavlova; David B. Chen; Taylor Ismaili; Shukuan Li; Jasmine Nguyen; Namit Singh; Laura K. Shawver; Lili

September 16, 2019 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 16, 2019 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File

September 16, 2019 EX-99.1

Engineered From an Expanded Genetic Alphabet for the Potential Treatment of Autoimmune Disorders Marcos E. Milla, Carolina E. Caffaro, Lina Ma, Ingrid B. Joseph, David B. Chen, Taylor Ismaili, Kristine M. San Jose, Yelena Pavlova, Namit Singh, Lilia

Exhibit 99.1 THOR-809: An IL-2 Engineered From an Expanded Genetic Alphabet for the Potential Treatment of Autoimmune Disorders Marcos E. Milla, Carolina E. Caffaro, Lina Ma, Ingrid B. Joseph, David B. Chen, Taylor Ismaili, Kristine M. San Jose, Yelena Pavlova, Namit Singh, Lilia K. Koriazova, Hans R. Aerni, Michael J. Pena, Jerod L. Ptacin INTRODUCTION RESULTS RESULTS CD4+ regulatory T cells (Tre

September 13, 2019 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 11, 2019 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File

September 4, 2019 8-K

Entry into a Material Definitive Agreement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 30, 2019 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File Num

August 1, 2019 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38756 SYNTHORX,

August 1, 2019 EX-99.1

Synthorx Reports Second Quarter Financial Results

EX-99.1 2 thor-ex9916.htm EX-99.1 Exhibit 99.1 Synthorx Reports Second Quarter Financial Results SAN DIEGO, CA – August 1, 2019 (GLOBE NEWSWIRE) - Synthorx, Inc. (Nasdaq: THOR), a clinical-stage biotechnology company developing optimized therapeutics for cancer and autoimmune disorders, today reported financial results and provided a business update for the second quarter ended June 30, 2019. “At

August 1, 2019 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8‑K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 1, 2019 Synthorx, Inc.

June 20, 2019 8-K

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 20, 2019 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File Numbe

June 10, 2019 8-K

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 7, 2019 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File Number

May 31, 2019 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 May 31, 2019 Date of Report (Date of earliest event reported) Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File Number)

May 31, 2019 EX-99.1

Using Synthetic Biology to Reprogram the Therapeutic Activity of

Exhibit 99.1 THOR-707: Using Synthetic Biology to Reprogram the Therapeutic Activity of Interleukin-2 (IL-2) Marcos E. Milla; Jerod L. Ptacin; Carolina E. Caffaro; Hans R. Aerni; Lina Ma; Laura K. Shawver; Lilia K. Koriazova; Ingrid B. Joseph Synthorx Inc. Research & Development, La Jolla, CA BACKGROUND Recombinant interleukin-2 (rIL-2 or aldesleukin) is an approved immunotherapy in melanoma and r

April 30, 2019 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38756 SYNTHORX,

April 30, 2019 EX-99.1

Synthorx Reports First Quarter Financial Results

Exhibit 99.1 Synthorx Reports First Quarter Financial Results SAN DIEGO, CA ? April 30, 2019 ? Synthorx, Inc. (Nasdaq: THOR), a biotechnology company using a first-of-its-kind Expanded Genetic Alphabet platform technology to discover and develop optimized biologics for cancer and autoimmune disorders, today reported financial results and provided a business update for the first quarter ended March

April 30, 2019 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

8-K 1 thor-8k20190430.htm 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8‑K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 30, 2019 Synthorx, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware (State or Other Jurisdiction of Incorporation) 001-38756 (Com

April 24, 2019 DEFA14A

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.__)

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

April 24, 2019 DEF 14A

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.__)

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

April 2, 2019 EX-99.1

A Novel

Exhibit 99.1 THOR-707, A Novel Not-alpha IL-2, Elicits Durable Pharmacodynamic Responses in Non-human Primates and, Efficacy as Single Agent and in Combination with Anti PD-1 in Multiple Syngeneic Mouse Models Ingrid B. Joseph; Lina Ma; Jerod L. Ptacin; Carolina E. Caffaro; Hans R. Aerni; Kristine M. San Jose; Michael J. Pena; Robert W. Herman; Yelena Pavlova; David B. Chen; Ken Bragstad; Shukuan

April 2, 2019 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 April 2, 2019 Date of Report (Date of earliest event reported) Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 001-38756 46-4709185 (State or other jurisdiction of incorporation) (Commission File Number

March 12, 2019 8-K

Material Modification to Rights of Security Holders, Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8?K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 12, 2019 Synthorx, Inc.

March 12, 2019 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 Form 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 Form 10-K (Mark One) ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-38756 SYNTHORX, INC.

March 12, 2019 S-8

As filed with the Securities and Exchange Commission on March 12, 2019

S-8 1 d720624ds8.htm S-8 As filed with the Securities and Exchange Commission on March 12, 2019 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT Under THE SECURITIES ACT OF 1933 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 46-4709185 (State or other jurisdiction of incorporation or organi

March 12, 2019 EX-99.1

Synthorx Reports Fourth Quarter and Full Year 2018 Financial Results Company Positioned for Upcoming 2019 Milestones After Successful IPO Raising $150.7 Million in Gross Proceeds Presented Preclinical Safety and Anti-Tumor Data on Lead Product Candid

Exhibit 99.1 Synthorx Reports Fourth Quarter and Full Year 2018 Financial Results Company Positioned for Upcoming 2019 Milestones After Successful IPO Raising $150.7 Million in Gross Proceeds Presented Preclinical Safety and Anti-Tumor Data on Lead Product Candidate THOR-707 at SITC 33rd Annual Meeting; Expect to File Investigational New Drug (IND) Application in Second Quarter of 2019 SAN DIEGO,

February 14, 2019 SC 13G/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1) Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) (

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1) Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 87167A103 (CUSIP Number) December 31, 2018 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule purs

February 14, 2019 EX-1

JOINT FILING AGREEMENT

EXHIBIT 1 JOINT FILING AGREEMENT This Joint Filing Agreement dated February 14, 2019 is by and between Camber Capital Management LP, a Delaware limited partnership, and Stephen DuBois, an individual (the foregoing are collectively referred to herein as the "Filers").

January 31, 2019 EX-99.1

Joint Filing Agreement

EX-99.1 2 d663542dex991.htm EX-99.1 EXHIBIT 99.1 Joint Filing Agreement The undersigned acknowledge and agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing statements. The unders

January 31, 2019 SC 13G/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. 1)* Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. 1)* Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 87167A 10 3 (CUSIP Number) December 11, 2018 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule

December 21, 2018 SC 13D

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13D UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )* Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 (Title of Class of Securities) 87167A 103 (CUSIP Number) J

SC 13D 1 d660728dsc13d.htm SC 13D SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13D UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )* Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 (Title of Class of Securities) 87167A 103 (CUSIP Number) Jay Lichter, Ph.D. Avalon Ventures 1134 Kline Street La Jolla, California 92037 (858) 348-2180 (Name, Address and Tel

December 21, 2018 EX-99.C

JOINT FILING AGREEMENT

EXHIBIT C JOINT FILING AGREEMENT In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of a statement on Schedule 13D (including amendments thereto) with respect to the Common Stock of Synthorx, Inc.

December 21, 2018 EX-99.B

FORM OF LOCK-UP AGREEMENT

EX-99.B 2 d660728dex99b.htm EX-99.B EXHIBIT B FORM OF LOCK-UP AGREEMENT , 2018 Jefferies LLC Leerink Partners LLC Evercore Group L.L.C. As Representatives of the Several Underwriters c/o Jefferies LLC 520 Madison Avenue New York, New York 10022 Leerink Partners LLC One Federal Street, 37th Floor Boston, Massachusetts 02110 and Evercore Group L.L.C. 55 East 52nd Street New York, New York 10055 RE:

December 20, 2018 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 19, 2018 Synthorx, Inc.

8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 19, 2018 Synthorx, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware (State or Other Jurisdiction of Incorporation) 001-38756 (Commission File Number)

December 20, 2018 EX-99.1

JOINT FILING AGREEMENT

EXHIBIT 1 JOINT FILING AGREEMENT The undersigned hereby agree that the Statement on this Schedule 13D, dated December 20, 2018 (the ?Schedule 13D?), with respect to the Shares of Synthorx, Inc.

December 20, 2018 SC 13D

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 Synthorx, Inc. (Name of Issuer) COMMON STOCK (Title of Class of Securities) 87167A103 (CUSIP Number) OrbiMed Advisors LLC OrbiMed Capital GP VII LLC 601 Lexington Avenue, 54th Floor New York, NY 10022 Telephone: (212) 739-6400 (Name, Address and Telephone Number of Person

December 19, 2018 SC 13G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )* Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 8

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )* Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 87167A 10 3 (CUSIP Number) December 11, 2018 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pu

December 19, 2018 EX-99.1

Joint Filing Agreement

EXHIBIT 99.1 Joint Filing Agreement The undersigned acknowledge and agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing statements. The undersigned acknowledge that each shall be

December 17, 2018 EX-99.2

Synthorx, Inc. 2018 Equity Incentive Plan and Forms of Stock Option Grant Notice, Option Agreement, Notice of Exercise, Restricted Stock Unit Grant Notice and Restricted Stock Unit Award Agreement thereunder.

Exhibit 99.2 SYNTHORX, INC. 2018 EQUITY INCENTIVE PLAN ADOPTED BY THE BOARD OF DIRECTORS: NOVEMBER 19, 2018 APPROVED BY THE STOCKHOLDERS: NOVEMBER 26, 2018 IPO DATE: DECEMBER 6, 2018 1. GENERAL. (a) Successor to and Continuation of Prior Plan. The Plan is intended as the successor to and continuation of the Synthorx, Inc. 2014 Equity Incentive Plan (the ?Prior Plan?). From and after 12:01 a.m. Pac

December 17, 2018 EX-1

JOINT FILING AGREEMENT

EXHIBIT 1 JOINT FILING AGREEMENT This Joint Filing Agreement dated December 17, 2018 is by and between Camber Capital Management LP, a Delaware limited partnership, and Stephen DuBois, an individual (the foregoing are collectively referred to herein as the "Filers").

December 17, 2018 SC 13D

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. ___)* Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities

SC 13D 1 tv509221sc13d.htm SC 13D OMB APPROVAL OMB Number: 3235-0145 Expires: February 28, 2009 Estimated average burden hours per response… 10.4 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. )* Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 87167

December 17, 2018 SC 13G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) (CUSIP Number) Dece

SC 13G 1 camberTHOR201813g.htm PRIMARY DOCUMENT UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 Synthorx, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 87167A103 (CUSIP Number) December 07, 2018 (Date of Event Which Requires Filing of this Statement) Check the appropriate

December 17, 2018 EX-99.1

JOINT FILING AGREEMENT

CUSIP No. 87167A103 Exhibit 1 JOINT FILING AGREEMENT This Joint Filing Agreement, dated as of December 14, 2018, is by and among RA Capital Management, LLC and Peter Kolchinsky (the foregoing are collectively referred to herein as the ?Filers?). Each of the Filers may be required to file with the United States Securities and Exchange Commission a statement on Schedule 13G and/or 13D with respect t

December 17, 2018 S-8

As filed with the Securities and Exchange Commission on December 17, 2018

S-8 1 d675636ds8.htm S-8 As filed with the Securities and Exchange Commission on December 17, 2018 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Synthorx, Inc. (Exact name of registrant as specified in its charter) Delaware 46-4709185 (State or other jurisdiction of incorporation or org

December 11, 2018 EX-3.2

Amended and Restated Bylaws (incorporated by reference to Exhibit 3.2 to the Registrant’s Current Report on Form 8-K, filed December 11, 2018).

Exhibit 3.2 AMENDED AND RESTATED BYLAWS OF SYNTHORX, INC. ARTICLE I OFFICES Section 1. Registered Office. The registered office of the corporation in the State of Delaware shall be in the City of Dover, County of Kent. Section 2. Other Offices. The corporation shall also have and maintain an office or principal place of business at such place as may be fixed by the corporation?s Board of Directors

December 11, 2018 EX-3.1

Amended and Restated Certificate of Incorporation (incorporated by reference to Exhibit 3.1 to the Registrant’s Current Report on Form 8-K, filed December 11, 2018).

Exhibit 3.1 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF SYNTHORX, INC. Laura Shawver hereby certifies that: ONE: She is the duly elected and acting Chief Executive Officer of Synthorx, Inc., a Delaware corporation. TWO: The date of filing of said corporation?s original certificate of incorporation with the Delaware Secretary of State was January 29, 2014 under the name Alinos, Inc. THREE:

December 11, 2018 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 11, 2018 Synthorx, Inc.

Form 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 11, 2018 Synthorx, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-38756 46-4709185 (State or Other Jurisdiction of Incorporation) (Commissi

December 7, 2018 POS EX

As filed with the Securities and Exchange Commission on December 6, 2018

POS EX As filed with the Securities and Exchange Commission on December 6, 2018 Registration No.

December 7, 2018 424B4

11,912,727 Shares Common Stock

Table of Contents Filed Pursuant to Rule 424(b)(4) Registration Nos. 333-228355 and 333-228700 PROSPECTUS 11,912,727 Shares Common Stock This is the initial public offering of Synthorx, Inc. We are offering 11,912,727 shares of our common stock. Prior to this offering, there has been no public market for our common stock. The initial public offering price of our common stock is $11.00 per share. O

December 6, 2018 S-1MEF

As filed with the U.S. Securities and Exchange Commission on December 6, 2018.

S-1MEF As filed with the U.S. Securities and Exchange Commission on December 6, 2018. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Synthorx, Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 2834 46-4709185 (State or Other Jurisdiction of Incorporation or Organizatio

December 6, 2018 8-A12B

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 Synthorx, Inc. (Exact name of registrant as speci

Form 8-A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 Synthorx, Inc.

December 4, 2018 CORRESP

Via EDGAR

Acceleration Request Via EDGAR December 4, 2018 U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attn: Ms. Irene Paik Re: Synthorx, Inc. Registration Statement on Form S-1 File No. 333-228355 Acceleration Request Requested Date: Thursday, December 6, 2018 Requested Time: 4:30 P.M. Eastern Time Ladies and Gentlemen: In accordance with

December 4, 2018 CORRESP

[Signature Page Follows]

Acceleration Request December 4, 2018 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Mail Stop 4720 Washington, D.C. 20549-3628 Attn: Ms. Irene Paik Re: Synthorx, Inc. (the “Company”) – Request for Acceleration Registration Statement on Form S-1 (File No. 333-228355) Ladies and Gentlemen: In accordance with Rule 461 under the Securities Act of

November 27, 2018 EX-3.1

Amended and Restated Certificate of Incorporation, as amended and currently in effect.

Exhibit 3.1 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF SYNTHORX, INC. (Pursuant to Sections 242 and 245 of the General Corporation Law of the State of Delaware) Synthorx, Inc., a corporation organized and existing under and by virtue of the provisions of the General Corporation Law of the State of Delaware (as may be amended from time to time, the ?General Corporation Law?), DOES HEREBY

November 27, 2018 S-1/A

As filed with the Securities and Exchange Commission on November 27, 2018

S-1/A 1 d613741ds1a.htm S-1/A Table of Contents As filed with the Securities and Exchange Commission on November 27, 2018 Registration No. 333-228355 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Synthorx, Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 2834 46-4709185

November 27, 2018 EX-10.6

Non-Employee Director Compensation Policy.

EX-10.6 Exhibit 10.6 SYNTHORX, INC. NON-EMPLOYEE DIRECTOR COMPENSATION POLICY Each member of the Board of Directors (the “Board”) who is not also serving as an employee of or consultant to Synthorx, Inc. (the “Company”) or any of its subsidiaries (each such member, an “Eligible Director”) will receive the compensation described in this Non-Employee Director Compensation Policy for his or her Board

November 27, 2018 EX-4.1

Form of Common Stock Certificate (incorporated by reference to Exhibit 4.1 to the Registrant’s Registration Statement on Form S-1, as amended (File No. 333-228355), filed November 27, 2018).

Exhibit 4.1

November 27, 2018 EX-10.4

Synthorx, Inc. 2018 Employee Stock Purchase Plan.

EX-10.4 Exhibit 10.4 SYNTHORX, INC. 2018 EMPLOYEE STOCK PURCHASE PLAN ADOPTED BY THE BOARD OF DIRECTORS: NOVEMBER 19, 2018 APPROVED BY THE STOCKHOLDERS: NOVEMBER 26, 2018 1. GENERAL; PURPOSE. (a) The Plan provides a means by which Eligible Employees of the Company and certain designated Related Corporations may be given an opportunity to purchase shares of Common Stock. The Plan permits the Compan

November 27, 2018 EX-1.1

Form of Underwriting Agreement.

Exhibit 1.1 [ ? ] Shares Synthorx, Inc. UNDERWRITING AGREEMENT [ ? ], 2018 JEFFERIES LLC LEERINK PARTNERS, LLC EVERCORE GROUP L.L.C. As Representatives of the several Underwriters c/o JEFFERIES LLC 520 Madison Avenue New York, New York 10022 c/o LEERINK PARTNERS LLC One Federal Street, 37th Floor Boston, Massachusetts 02110 and c/o EVERCORE GROUP L.L.C. 55 East 52nd Street New York, New York 10055

November 27, 2018 EX-10.3

Synthorx, Inc. 2018 Equity Incentive Plan and Forms of Stock Option Grant Notice, Option Agreement, Notice of Exercise, Restricted Stock Unit Grant Notice and Restricted Stock Unit Award Agreement thereunder.

EX-10.3 Exhibit 10.3 SYNTHORX, INC. 2018 EQUITY INCENTIVE PLAN ADOPTED BY THE BOARD OF DIRECTORS: NOVEMBER 19, 2018 APPROVED BY THE STOCKHOLDERS: NOVEMBER 26, 2018 IPO DATE: [ ], 2018 1. GENERAL. (a) Successor to and Continuation of Prior Plan. The Plan is intended as the successor to and continuation of the Synthorx, Inc. 2014 Equity Incentive Plan (the “Prior Plan”). From and after 12:01 a.m. Pa

November 20, 2018 CORRESP

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETED ASTERISKS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE COMMISSION PURSUANT TO 17 CFR §200.83.

CORRESP *FOIA Confidential Treatment Request* Confidential Treatment Requested by Synthorx, Inc.

November 13, 2018 EX-10.1

Form of Indemnity Agreement by and between the Registrant and its directors and officers.

Exhibit 10.1 INDEMNITY AGREEMENT THIS INDEMNITY AGREEMENT (this ?Agreement?) dated as of , 20 , is made by and between SYNTHORX, INC., a Delaware corporation (the ?Company?), and (?Indemnitee?). RECITALS A. The Company desires to attract and retain the services of highly qualified individuals as directors, officers, employees and agents. B. The Company?s Amended and Restated Bylaws (the ?Bylaws?)

November 13, 2018 CORRESP

Cooley LLP 4401 Eastgate Mall San Diego, CA 92121-1909 t: (858) 550-6000 f: (858) 550-6420 cooley.com

CORRESP Kenneth J. Rollins +1 858 550 6136 [email protected] November 13, 2018 U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attn: Irene Paik Re: Synthorx, Inc. Amendment No. 2 to Draft Registration Statement on Form S-1 Submitted October 23, 2018 CIK No. 0001609727 Dear Ms. Paik: On behalf of Synthorx, Inc. (the “Company”), we

November 13, 2018 EX-10.2

Synthorx, Inc. 2014 Equity Incentive Plan and Forms of Option Grant Notice, Option Agreement, Notice of Exercise and Early Exercise Stock Purchase Agreement thereunder, as amended.

EX-10.2 Exhibit 10.2 SYNTHORX, INC. 2014 EQUITY INCENTIVE PLAN ADOPTED BY THE BOARD OF DIRECTORS: MAY 27, 2014 APPROVED BY THE STOCKHOLDERS: MAY 27, 2014 AMENDED BY THE BOARD OF DIRECTORS: JUNE 24, 2015 APPROVED BY THE STOCKHOLDERS: JULY 20, 2015 AMENDED BY THE BOARD OF DIRECTORS: JULY 12, 2016 APPROVED BY THE STOCKHOLDERS: JULY 13, 2016 AMENDED BY THE BOARD OF DIRECTORS: APRIL 11, 2018 APPROVED B

November 13, 2018 EX-10.15

First Amendment to License Agreement, dated September 10, 2018, by and between the Registrant and The Scripps Research Institute.

Exhibit 10.15 ***Text Omitted and Filed Separately with the Securities and Exchange Commission. Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the Securities Act of 1933, as amended. FIRST AMENDMENT TO LICENSE AGREEMENT This is an Amendment, dated as of September 10, 2018 (this ?First Amendment?), to the License Agreement dated July 31, 2014 (the ?Agreement?),

November 13, 2018 EX-10.14

Offer Letter Agreement, dated July 20, 2018, by and between the Registrant and Joseph A. Leveque, Ph.D.

EX-10.14 Exhibit 10.14 July 20, 2018 Joseph A. Leveque, M.D. 3 Blu Harbor Boulevard #307 Redwood City, CA 94063 VIA ELECTRONIC MAIL CONFIDENTIAL [email protected] Dear Joe, We are very pleased to extend to you the offer of employment for the position of Chief Medical Officer reporting to Laura Shawver, Ph.D. The following outlines your offer of employment: Start Date: July 30, 2018 Compensation:

November 13, 2018 EX-10.12

Offer Letter Agreement, dated October 19, 2017, by and between the Registrant and Laura Shawver, Ph.D.

Exhibit 10.12 October 15, 2017 Laura Shawver, Ph.D. 7135 Fay La Jolla, CA 92037 VIA ELECTRONIC MAIL CONFIDENTIAL [email protected] Dear Laura, We are very pleased to extend to you the offer of employment for the position of President and Chief Executive Officer. You will also serve as a Director on the Board of Directors of Synthorx, Inc. The following outlines your offer of Employment: Start

November 13, 2018 EX-10.11

Office Sublease, dated May 6, 2014, by and between the Registrant and COI Pharmaceuticals, Inc.

Exhibit 10.11 OFFICE SUBLEASE 11099 North Torrey Pines Road, San Diego, California KEY PROVISIONS SUMMARY Sublease Date: May 6, 2014 Sublandlord: COI PHARMACEUTICALS, INC., a Delaware corporation Subtenant: SYNTHORX, INC., a Delaware corporation Premises: Approximately 8,636 rentable square feet of space located in Suite 200/230 in the Master Property, more particularly shown on the floor plan att

November 13, 2018 EX-10.7

License Agreement, dated July 31, 2014, by and between the Registrant and The Scripps Research Institute.

Exhibit 10.7 ***Text Omitted and Filed Separately with the Securities and Exchange Commission. Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the Securities Act of 1933, as amended. LICENSE AGREEMENT by and between THE SCRIPPS RESEARCH INSTITUTE, a California nonprofit public benefit corporation and SYNTHORX, INC., a Delaware corporation LICENSE AGREEMENT THIS

November 13, 2018 EX-3.4

Form of Amended and Restated Bylaws to become effective upon the completion of this offering.

Exhibit 3.4 AMENDED AND RESTATED BYLAWS OF SYNTHORX, INC. ARTICLE I OFFICES Section 1. Registered Office. The registered office of the corporation in the State of Delaware shall be in the City of Dover, County of Kent. Section 2. Other Offices. The corporation shall also have and maintain an office or principal place of business at such place as may be fixed by the corporation?s Board of Directors

November 13, 2018 EX-4.2

Amended and Restated Investors’ Rights Agreement, dated April 12, 2018, by and among the Registrant and certain of its securityholders, as amended (incorporated by reference to Exhibit 4.2 to the Registrant’s Registration Statement on Form S-1, as amended (File No. 333-228355), filed November 13, 2018).

EX-4.2 Exhibit 4.2 AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT THIS AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT (this “Agreement”), is made as of the 12th day of April, 2018, by and among Synthorx, Inc., a Delaware corporation (the “Company”), and each of the investors listed on Schedule A attached hereto, each of which is referred to in this Agreement as an “Investor” and any Additional

November 13, 2018 EX-10.17

Amendment to Office Sublease, dated November 12, 2018, by and between the Registrant and COI Pharmaceuticals, Inc.

Exhibit 10.17 FIRST AMENDMENT TO OFFICE SUBLEASE AGREEMENT THIS FIRST AMENDMENT TO OFFICE SUBLEASE AGREEMENT (this ?Amendment?) is entered into as of November 12, 2018 (the ?Effective Date?), by and between COI PHARMACEUTICALS, INC., a Delaware corporation (?Sublandlord?), and SYNTHORX, INC., a Delaware corporation (?Subtenant?). Sublandlord and Subtenant may be referred to herein collectively as

November 13, 2018 EX-10.5

Synthorx, Inc. 2018 Change in Control and Severance Benefit Plan.

Exhibit 10.5 SYNTHORX, INC. CHANGE IN CONTROL AND SEVERANCE BENEFIT PLAN APPROVED BY THE BOARD OF DIRECTORS: OCTOBER 11, 2018 Section 1. INTRODUCTION. The Synthorx, Inc. Change in Control and Severance Benefit Plan (the ?Plan?) is hereby established effective [ ], 2018 (the ?Effective Date?). The purpose of the Plan is to provide for the payment of severance benefits to eligible employees of Synth

November 13, 2018 EX-10.16

Lease, dated September 21, 2018, by and between the Registrant and HCP Torrey Pines, LLC.

Exhibit 10.16 11099 NORTH TORREY PINES ROAD LEASE This Lease (this ?Lease?), dated as of the date set forth in Section 1 of the Summary of Basic Lease Information (the ?Summary?), below, is made by and between HCP TORREY PINES, LLC, a Delaware limited liability company (?Landlord?), and SYNTHORX INC., a Delaware corporation (?Tenant?). SUMMARY OF BASIC LEASE INFORMATION TERMS OF LEASE DESCRIPTION

November 13, 2018 EX-3.3

Amended and Restated Bylaws, as currently in effect.

Exhibit 3.3 AMENDED AND RESTATED BYLAWS OF SYNTHORX, INC. (A DELAWARE CORPORATION) ARTICLE I OFFICES Section 1. Registered Office. The registered office of the corporation in the State of Delaware shall be in the City of Wilmington, County of New Castle. Section 2. Other Offices. The corporation shall also have and maintain an office or principal place of business at such place as may be fixed by

November 13, 2018 EX-10.13

Employment Agreement, dated July 14, 2017, by and between the Registrant and Marcos Milla, Ph.D.

Exhibit 10.13 SYNTHORYX, INC. EMPLOYMENT AGREEMENT This Employment Agreement (this ?Agreement?), is made and entered into as of July 14, 2017 (the ?Effective Date?), by and between Marcos E. Milla, Ph.D. (?Employee?) and Synthorx, Inc. (the ?Company?). 1. Employment by the Company. 1.1 Position. Employee shall serve as the Company?s Senior Vice President of Research, initially reporting to the Com

November 13, 2018 EX-10.9

Master Services Agreement and Scope of Work for Contract Manufacturing Services, dated April 12, 2018, by and between the Registrant and Cytovance Biologics, Inc.

EX-10.9 Exhibit 10.9 ***Text Omitted and Filed Separately with the Securities and Exchange Commission. Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the Securities Act of 1933, as amended. SYNTHORX, INC. MASTER SERVICES AGREEMENT THIS MASTER SERVICES AGREEMENT (this “Agreement”) is entered into as of April 12, 2018 (the “Effective Date”), by and between SYNTHO

November 13, 2018 EX-3.2

Form of Amended and Restated Certificate of Incorporation to become effective immediately prior to the completion of this offering.

EX-3.2 Exhibit 3.2 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF SYNTHORX, INC. Laura Shawver hereby certifies that: ONE: She is the duly elected and acting Chief Executive Officer of Synthorx, Inc., a Delaware corporation. TWO: The date of filing of said corporation’s original certificate of incorporation with the Delaware Secretary of State was January 29, 2014 under the name Alinos, Inc.

November 13, 2018 S-1

Power of Attorney (included on the signature page of the Registration Statement on Form S-1, as amended (File No. 333-228355), filed with the Commission on November 13, 2018 and incorporated herein by reference).

Table of Contents As filed with the Securities and Exchange Commission on November 13, 2018 Registration No.

November 13, 2018 EX-10.8

Research Funding and Option Agreement, dated July 31, 2014, by and between the Registrant and The Scripps Research Institute, as amended on September 2, 2015, September 9, 2016, October 16, 2017 and August 16, 2018.

Exhibit 10.8 ***Text Omitted and Filed Separately with the Securities and Exchange Commission. Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the Securities Act of 1933, as amended. RESEARCH FUNDING AND OPTION AGREEMENT by and between THE SCRIPPS RESEARCH INSTITUTE a California nonprofit public benefit corporation and Synthorx, Inc., a Delaware corporation RESE

November 13, 2018 EX-3.1

Amended and Restated Certificate of Incorporation, as currently in effect.

Exhibit 3.1 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF SYNTHORX, INC. (Pursuant to Sections 242 and 245 of the General Corporation Law of the State of Delaware) Synthorx, Inc., a corporation organized and existing under and by virtue of the provisions of the General Corporation Law of the State of Delaware (as may be amended from time to time, the ?General Corporation Law?), DOES HEREBY

November 13, 2018 EX-10.10

Support Services Agreement, dated October 10, 2017, by and between the Registrant and COI Pharmaceuticals, Inc.

EX-10.10 Exhibit 10.10 ***Text Omitted and Filed Separately with the Securities and Exchange Commission. Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the Securities Act of 1933, as amended. SUPPORT SERVICES AGREEMENT THIS SUPPORT SERVICES AGREEMENT (this “Agreement”) is made and entered into as of October 10, 2017 (the “Effective Date”), by and between SYNTHO

October 23, 2018 EX-3.2

AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF SYNTHORX, INC.

Exhibit 3.2 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF SYNTHORX, INC. Laura Shawver hereby certifies that: ONE: She is the duly elected and acting Chief Executive Officer of Synthorx, Inc., a Delaware corporation. TWO: The date of filing of said corporation’s original certificate of incorporation with the Delaware Secretary of State was January 29, 2014 under the name Alinos, Inc. THREE:

October 23, 2018 DRSLTR

Cooley LLP 4401 Eastgate Mall San Diego, CA 92121-1909 t: (858) 550-6000 f: (858) 550-6420 cooley.com

DRSLTR Kenneth J. Rollins +1 858 550 6136 [email protected] October 23, 2018 U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attn: Irene Paik Re: Synthorx, Inc. Amendment No. 1 to Draft Registration Statement on Form S-1 Submitted October 2, 2018 CIK No. 0001609727 Dear Ms. Paik: On behalf of Synthorx, Inc. (the “Company”), we are

October 23, 2018 DRS/A

Draft Registration Statement No. 3, as submitted confidentially to the Securities and Exchange Commission on October 23, 2018

DRS/A Table of Contents Draft Registration Statement No. 3, as submitted confidentially to the Securities and Exchange Commission on October 23, 2018 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Synthorx, Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 2834 46-4709

October 23, 2018 EX-10.5

SYNTHORX, INC. CHANGE IN CONTROL AND SEVERANCE BENEFIT PLAN APPROVED BY THE BOARD OF DIRECTORS: OCTOBER 11, 2018

Exhibit 10.5 SYNTHORX, INC. CHANGE IN CONTROL AND SEVERANCE BENEFIT PLAN APPROVED BY THE BOARD OF DIRECTORS: OCTOBER 11, 2018 Section 1. INTRODUCTION. The Synthorx, Inc. Change in Control and Severance Benefit Plan (the ?Plan?) is hereby established effective [ ], 2018 (the ?Effective Date?). The purpose of the Plan is to provide for the payment of severance benefits to eligible employees of Synth

October 23, 2018 EX-3.4

AMENDED AND RESTATED SYNTHORX, INC. ARTICLE I

Exhibit 3.4 AMENDED AND RESTATED BYLAWS OF SYNTHORX, INC. ARTICLE I OFFICES Section 1. Registered Office. The registered office of the corporation in the State of Delaware shall be in the City of Dover, County of Kent. Section 2. Other Offices. The corporation shall also have and maintain an office or principal place of business at such place as may be fixed by the corporation’s Board of Directors

October 23, 2018 EX-10.1

INDEMNITY AGREEMENT

Exhibit 10.1 INDEMNITY AGREEMENT THIS INDEMNITY AGREEMENT (this “Agreement”) dated as of , 20 , is made by and between SYNTHORX, INC., a Delaware corporation (the “Company”), and (“Indemnitee”). RECITALS A. The Company desires to attract and retain the services of highly qualified individuals as directors, officers, employees and agents. B. The Company’s Amended and Restated Bylaws (the “Bylaws”)

October 2, 2018 DRSLTR

Cooley LLP 4401 Eastgate Mall San Diego, CA 92121-1909 t: (858) 550-6000 f: (858) 550-6420 cooley.com

Kenneth J. Rollins +1 858 550 6136 [email protected] October 2, 2018 U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attn: Ada D. Sarmento Re: Synthorx, Inc. Draft Registration Statement on Form S-1 Submitted August 31, 2018 CIK No. 0001609727 Dear Ms. Sarmento: On behalf of Synthorx, Inc. (the “Company”), we are responding to the

October 2, 2018 EX-10.14

11099 NORTH TORREY PINES ROAD

Exhibit 10.14 11099 NORTH TORREY PINES ROAD LEASE This Lease (this ?Lease?), dated as of the date set forth in Section 1 of the Summary of Basic Lease Information (the ?Summary?), below, is made by and between HCP TORREY PINES, LLC, a Delaware limited liability company (?Landlord?), and SYNTHORX INC., a Delaware corporation (?Tenant?). SUMMARY OF BASIC LEASE INFORMATION TERMS OF LEASE DESCRIPTION

October 2, 2018 EX-10.13

FIRST AMENDMENT TO LICENSE AGREEMENT

Exhibit 10.13 ***Text Omitted and Filed Separately with the Securities and Exchange Commission. Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the Securities Act of 1933, as amended. FIRST AMENDMENT TO LICENSE AGREEMENT This is an Amendment, dated as of September 10, 2018 (this “First Amendment”), to the License Agreement dated July 31, 2014 (the “Agreement”),

October 2, 2018 DRS/A

Draft Registration Statement No. 2, as submitted confidentially to the Securities and Exchange Commission on October 2, 2018

Table of Contents Draft Registration Statement No. 2, as submitted confidentially to the Securities and Exchange Commission on October 2, 2018 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Synthorx, Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 2834 46-4709185 (St

August 31, 2018 EX-4.2

AMENDED AND RESTATED INVESTORS? RIGHTS AGREEMENT

EX-4.2 Exhibit 4.2 AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT THIS AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT (this “Agreement”), is made as of the 12th day of April, 2018, by and among Synthorx, Inc., a Delaware corporation (the “Company”), and each of the investors listed on Schedule A attached hereto, each of which is referred to in this Agreement as an “Investor” and any Additional

August 31, 2018 EX-3.1

AMENDED AND RESTATED CERTIFICATE OF INCORPORATION SYNTHORX, INC. (Pursuant to Sections 242 and 245 of the General Corporation Law of the State of Delaware)

EX-3.1 Exhibit 3.1 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF SYNTHORX, INC. (Pursuant to Sections 242 and 245 of the General Corporation Law of the State of Delaware) Synthorx, Inc., a corporation organized and existing under and by virtue of the provisions of the General Corporation Law of the State of Delaware (as may be amended from time to time, the “General Corporation Law”), DOES

August 31, 2018 EX-10.12

11099 N. Torrey Pines Road, Suite 290, La Jolla, CA 92037 Main: (858) 750-4700 Fax: (858) 750-4701

EX-10.12 13 filename13.htm Exhibit 10.12 July 20, 2018 Joseph A. Leveque, M.D. 3 Blu Harbor Boulevard #307 Redwood City, CA 94063 VIA ELECTRONIC MAIL CONFIDENTIAL [email protected] Dear Joe, We are very pleased to extend to you the offer of employment for the position of Chief Medical Officer reporting to Laura Shawver, Ph.D. The following outlines your offer of employment: Start Date: July 30,

August 31, 2018 EX-10.9

OFFICE SUBLEASE 11099 North Torrey Pines Road, San Diego, California KEY PROVISIONS SUMMARY

Exhibit 10.9 OFFICE SUBLEASE 11099 North Torrey Pines Road, San Diego, California KEY PROVISIONS SUMMARY Sublease Date: May 6, 2014 Sublandlord: COI PHARMACEUTICALS, INC., a Delaware corporation Subtenant: SYNTHORX, INC., a Delaware corporation Premises: Approximately 8,636 rentable square feet of space located in Suite 200/230 in the Master Property, more particularly shown on the floor plan atta

August 31, 2018 EX-10.10

11099 N. Torrey Pines Road, Suite 290, La Jolla, CA 92037 Main: (858) 750-4700 Fax: (858) 750-4701

Exhibit 10.10 October 15, 2017 Laura Shawver, Ph.D. 7135 Fay La Jolla, CA 92037 VIA ELECTRONIC MAIL CONFIDENTIAL [email protected] Dear Laura, We are very pleased to extend to you the offer of employment for the position of President and Chief Executive Officer. You will also serve as a Director on the Board of Directors of Synthorx, Inc. The following outlines your offer of Employment: Start

August 31, 2018 EX-3.3

AMENDED AND RESTATED BYLAWS SYNTHORX, INC. (A DELAWARE CORPORATION) ARTICLE I

Exhibit 3.3 AMENDED AND RESTATED BYLAWS OF SYNTHORX, INC. (A DELAWARE CORPORATION) ARTICLE I OFFICES Section 1. Registered Office. The registered office of the corporation in the State of Delaware shall be in the City of Wilmington, County of New Castle. Section 2. Other Offices. The corporation shall also have and maintain an office or principal place of business at such place as may be fixed by

August 31, 2018 DRS

As submitted confidentially to the Securities and Exchange Commission on August 31, 2018

Table of Contents As submitted confidentially to the Securities and Exchange Commission on August 31, 2018 Registration No.

August 31, 2018 EX-10.7

SYNTHORX, INC. MASTER SERVICES AGREEMENT

EX-10.7 Exhibit 10.7 ***Text Omitted and Filed Separately with the Securities and Exchange Commission. Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the Securities Act of 1933, as amended. SYNTHORX, INC. MASTER SERVICES AGREEMENT THIS MASTER SERVICES AGREEMENT (this “Agreement”) is entered into as of April 12, 2018 (the “Effective Date”), by and between SYNTHO

August 31, 2018 EX-10.6

BUDGET Principal Investigator/Program Director (Last, First, Middle): Romesberg, Floyd BUDGET PERSONNEL (Applicant organization only) % YEAR 1 NAME ROLE ON PROJECT EFFORT ON PROJ. SALARY/ FRINGE Romesberg, Floyd Principal Investigator […***…] […***…]

Exhibit 10.6 ***Text Omitted and Filed Separately with the Securities and Exchange Commission. Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the Securities Act of 1933, as amended. RESEARCH FUNDING AND OPTION AGREEMENT by and between THE SCRIPPS RESEARCH INSTITUTE a California nonprofit public benefit corporation and Synthorx, Inc., a Delaware corporation RESE

August 31, 2018 EX-10.8

SUPPORT SERVICES AGREEMENT

EX-10.8 Exhibit 10.8 ***Text Omitted and Filed Separately with the Securities and Exchange Commission. Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the Securities Act of 1933, as amended. SUPPORT SERVICES AGREEMENT THIS SUPPORT SERVICES AGREEMENT (this “Agreement”) is made and entered into as of October 10, 2017 (the “Effective Date”), by and between SYNTHORX

August 31, 2018 EX-10.11

SYNTHORYX, INC. EMPLOYMENT AGREEMENT

EX-10.11 Exhibit 10.11 SYNTHORYX, INC. EMPLOYMENT AGREEMENT This Employment Agreement (this “Agreement”), is made and entered into as of July 14, 2017 (the “Effective Date”), by and between Marcos E. Milla, Ph.D. (“Employee”) and Synthorx, Inc. (the “Company”). 1. Employment by the Company. 1.1 Position. Employee shall serve as the Company’s Senior Vice President of Research, initially reporting t

August 31, 2018 EX-10.5

LICENSE AGREEMENT by and between THE SCRIPPS RESEARCH INSTITUTE, a California nonprofit public benefit corporation SYNTHORX, INC., a Delaware corporation

Exhibit 10.5 ***Text Omitted and Filed Separately with the Securities and Exchange Commission. Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the Securities Act of 1933, as amended. LICENSE AGREEMENT by and between THE SCRIPPS RESEARCH INSTITUTE, a California nonprofit public benefit corporation and SYNTHORX, INC., a Delaware corporation LICENSE AGREEMENT THIS

August 31, 2018 EX-10.2

SYNTHORX, INC. 2014 EQUITY INCENTIVE PLAN ADOPTED BY THE BOARD OF DIRECTORS: MAY 27, 2014 APPROVED BY THE STOCKHOLDERS: MAY 27, 2014 AMENDED BY THE BOARD OF DIRECTORS: JUNE 24, 2015 APPROVED BY THE STOCKHOLDERS: JULY 20, 2015 AMENDED BY THE BOARD OF

EX-10.2 Exhibit 10.2 SYNTHORX, INC. 2014 EQUITY INCENTIVE PLAN ADOPTED BY THE BOARD OF DIRECTORS: MAY 27, 2014 APPROVED BY THE STOCKHOLDERS: MAY 27, 2014 AMENDED BY THE BOARD OF DIRECTORS: JUNE 24, 2015 APPROVED BY THE STOCKHOLDERS: JULY 20, 2015 AMENDED BY THE BOARD OF DIRECTORS: JULY 12, 2016 APPROVED BY THE STOCKHOLDERS: JULY 13, 2016 AMENDED BY THE BOARD OF DIRECTORS: APRIL 11, 2018 APPROVED B

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